The present invention relates to a spirometer or like respiratory testing device for use in testing lung and airway capacity or function of a patient and/or for measuring the amount or volume and/or speed or flow of air that can be inhaled and/or exhaled by the patient, and more particularly, the present invention relates to a portable, lightweight, hand-held spirometer particularly suitable for home and personal use, although equally capable of being used in hospitals, doctor's offices, and like institutions. The present invention is also directed to a system, software, and method for obtaining, storing and displaying the results of spirometry tests.
In general, a spirometry test measures the air entering and leaving the lungs and airways and is often used as a preliminary test for accessing the health condition of a patient's lungs and airways as well as a means for periodically tracking the progress of disease treatment and effect of medication. The spirometry test is typically performed using a device known as a spirometer, and the data provided by the test is often provided graphically in the form of a “volume-time curve” in which volume in liters is shown along the Y-axis and time in seconds is shown along the X-axis and/or in the form of a “flow-volume loop” in which the rate of airflow is shown on the Y-axis and the total volume inspired or expired is shown on the X-axis.
By way of example, a few common parameters that may be measured during respiratory testing include: Forced Vital Capacity (FVC) which is the total volume of air that can be forcibly blown out after full inspiration; Forced Expiratory Volume (FEV) at timed intervals (for instance, at 1.0 second (FEV1)); Forced Expiratory Flow (FEF) which is the average flow (speed) of air coming out of the lungs and airways during a specified period of the expiration; and Peak Expiratory Flow (PEF) which is the maximum flow (speed) of air during maximum expiration initiated after full inspiration. These parameters are often provided in raw data form (i.e., in liters, liters/second, liters/minute, etc.) and as percent predicted (i.e., a percent of a predicted value for a patient of similar age, height, weight, gender and ethnicity).
Each test is typically repeated three times to ensure reproducibility. The obtained results of the tests are highly dependent on patient cooperation and effort. For meaningful and valid test results to be obtained, the patient must provide vigorous and maximum respiratory effort for full expiration and/or inhalation. Typically, if the test is given during an office visit or at a hospital or the like, the patient will be coached and motivated by the attending nurse, physician or technician to keep exhaling as hard as possible for a predetermined period of time (i.e. “keep going, don't stop”). However, no such assistance is typically provided during home use of a spirometer; thus, the obtained home test results may not necessarily be valid if maximum effort is not provided throughout the duration of full expiration or inhalation.
Some basic examples of spirometers and like instruments are disclosed by U.S. Patent Application Publication Nos. 2006/0282002 A1 of Wang et al., 2007/0239058 A1 of Krasilchikov et al., 2009/0270751 A1 of Peng et al., 2006/0100537 A1 of Williams et al. and 2005/0256421 A1 of Bryant et al. and by U.S. Pat. No. 5,518,002 issued to Wolf et al., U.S. Pat. No. 5,816,246 issued to Mirza, U.S. Pat. No. 6,447,459 B1 issued to Larom, U.S. Pat. No. 7,282,032 B2 issued to Miller, U.S. Pat. No. 4,122,842 issued to Pikul, D.339,635 issued to Waterson et al., U.S. Pat. No. 7,390,305 B2 issued to Nuttall, U.S. Pat. Nos. 6,019,731 and 6,042,551 issued to Harbrecht et al., U.S. Pat. No. 4,736,750 issued to Valdespino et al., U.S. Pat. No. 4,991,591 issued to Jones et al., U.S. Pat. Nos. 5,715,831 and 6,113,549 issued to Johnson, U.S. Pat. No. 6,176,833 B1 issued to Thomson, U.S. Pat. No. 4,635,647 issued to Choksi, U.S. Pat. No. 4,495,944 issued to Brisson et al., U.S. Pat. No. 6,238,353 issued to Weinstein et al., U.S. Pat. No. 6,656,129 B2 issued to Niles et al. and U.S. Pat. No. 7,625,345 B2 issued to Quinn.
While known spirometers and like respiratory testing instruments may function in an acceptable manner, there continues to be a need for a portable personal spirometer having improved features with respect to ease of use and ability to readily and reproducibly obtain meaningful, valid test results so that progress of treatment and effect of medication over an extended period of time can be tracked in a reliable manner. For instance, a spirometer that is lightweight and compact and enables unsupervised use of the spirometer at home or the like yet still generates meaningful, reliable and valid test results that can be saved and studied at a later time by a patient, nurse, doctor or physician is desired.